In the art of shingle manufacture, it was commonplace for many years that shingles were made of natural materials, such as slate, cedar shakes or made as tiles, from clay or like materials.
It has developed that natural-appearing shingles have been made by various molding and/or lamination processes whereby synthetic shingles have the appearance of natural slate shingles, natural wood shake shingles, or tiles.
Such synthetic shingles have a number of advantages, including the ability to build into the materials of construction of the shingle, various features, such as algae resistance, ultraviolet light resistance, color stabilizers and enhancers that are able to avoid discolorations by oxidation or other phenomena, heat reflectivity, and many other features.
When synthetic shingles are molded, the molding process allows one to provide surface irregularities that, while being intentionally planned and predetermined, yield in the final product the appearance of natural materials. For example, natural slate shingles do not generally haw completely uniform and smooth surfaces. Rather, they have minor depressions and irregularities. With the molding of synthetic shingles, such minor depressions and irregularities can be molded into the shingle.